Rethinking Adaptation - the Evolution of Altruism

Altruism

In evolutionary biology, altruism is defined as an act that increases another individual's fitness at a cost to one's own.

Fitness

The ability of an organism to survive and reproduce, contributing to the gene pool of the next generation.

Mutualism

A relationship where two or more individuals cooperate for mutual fitness benefits.

Reciprocal altruism

A form of altruism where one individual helps another with the expectation of future help in return.

Kin Selection

The evolutionary strategy that favors reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction.

Hamilton's Rule

A principle that states a gene for altruistic behavior will spread in a population if the benefits to related individuals, weighted by their genetic relatedness, exceed the costs to the altruist.

Teleology

The explanation of phenomena by the purpose they serve rather than by postulated causes.

Evolutionary Adaptation

The process by which a species becomes better suited to its environment through evolution.

Eusociality

A high level of social organization characterized by cooperative brood care, overlapping generations, and division of labor into reproductive and non-reproductive groups.

Parental care

A common example of altruism in nature, where parents invest resources in raising their offspring.

Cooperation

The process where two or more individuals work together towards a common goal, which can enhance fitness.

Manipulation in Altruism

Behavior that may appear altruistic but is actually a strategy to exploit the parental care instincts of others.

Blood sharing in vampire bats

A classic example of reciprocal altruism where well-fed bats regurgitate blood to feed hungry companions.

Sexual reproduction

The process by which offspring are produced through the combination of genetic material from two parents, increasing genetic diversity.

Existential Prime Directive

The idea that the defining characteristic of life is survival, which necessitates adaptation and reproduction.

Mitochondria

Organelle within cells believed to have originated from independent, free-living cells that became symbiotic with eukaryotic cells.

Selfish Gene Theory

A perspective that posits genes are the primary unit of natural selection and act in ways to maximize their own replication.

Evolved Altruism

Altruistic behaviour evolved because it is adaptive; it increases the fitness of others at a cost to oneself.

Autopoiesis

The concept of self-organization in living organisms.

Purpose of Life

Purpose arises from the existential prime directive for life and promotes genes.

Pied Wagtails Example

Two birds cooperate to defend a winter-feeding territory, improving their feeding rate despite shared costs.

Lion Hunting Success

Lionesses improve hunting success by cooperating with others, compensating for meat sharing.

Cheating in Reciprocity

The possibility of individuals failing to reciprocate can be mitigated by recognizing cheats.

Begging Behavior of Nestling Birds

Nestling chicks alter their begging volume based on relatedness and food shortages.

Kin-selection

The strategy where individuals are more likely to help those with whom they share a genetic relationship.

Hamilton's Coefficient

The probability that a copy of a gene is shared between individuals; influences altruistic behavior.

Recognition of Kin

Mechanisms like learning and phenotype matching help animals recognize their kin.

Multi-level Selection

Combines individual selection with group selection to enhance fitness through cooperation within species clusters.

Gene Culture Co-evolution

The independent evolution of culture and genes over time, functioning as another level of selection.

Human Birth Cooperation

A process that requires cooperation, as difficulty arises in delivering a fetus without assistance, often from midwives.